This scarf has an odd inspiration. I saw a printed design on the edge of a dress, and somehow thought it looked like the double-helical DNA.
Coincidentally that night, one of my favourite T.V shows (The Big Bang Theory) aired an old episode where somehow the otherwise in-the-background DNA model in Sheldon & Leonard’s living room seemed to loom really large .. tada! Scarf born!
(Sheldon in his ‘Sheldon Cooper Fun with flags’ with Penny’ .. and you can see the DNA helix behind Sheldon :)

This scarf is worked from the bottom up, and though a long repeat, is not a difficult one. It also allows you to increase the length as per your choice, and width too, if you chose a thicker yarn.
While this yarn has been tested by the designer in light fingering 3 ply yarn, it is a design that can work with any ply yarn.

This pattern is also available at http://www.craftsy.com/pattern/crocheting/accessory/helic...

This pattern has been tested using :
a) 3-ply light acrylic yarn, 50g / 285 yds ; 4 mm crochet hook ;

b) Caron One Pound , 9 oz / 574 yds ; I crochet hook
Comments : Clear instructions and photos , took about 5-6 hrs ; planning on making this again;
it is pretty, fast, easy, and flexible in sizing with a change in yarn and/or hook.
Skill level by tester : Easy

c) Shibui Knits Linen (fingering weight chain-plied 100% linen), 244 yards ; US size G, 4.0mm crochet hook ;
Gauge : blocked, 14 trc and 6 rows = 4”;
Comments : Instructions & photos good , took about 10 hrs ; I find this design decorative and very versatile for a variety of fibers and yarn weights. It would be easy to add beads at the picots for an even more decorative look.
Skill level by tester : advanced beginner

d) Bernat Baby Jacard , half skein/50g/173yd , G crochet hook (4.25mm) ; GAUGE: 16 sc 4x4 in ;
Comments : Clear instructions ; Photos : Extremely helpful, I liked the photos to confirm placement of the group stitches and to make sure I had read the directions correctly. They were great to confirm repeats ; took about 5-6 hrs as I was not able to sit down for more than 15 mins at a stretch.
Skill level by tester : Experienced beginner